This invention relates to an improved system for use in the rapid temporary repair of severed or cut cables having optical fibers therein.
In present day fiber optic long line telephone communications, fiber optic cables containing anywhere between 12 to 72 fibers are employed which permit a high volume of telephone communications to be conducted. However, due to the nature of the material of the cable, i.e, the fibers which are extremely fragile, these cables are often subject to damage from a variety of different sources, for example, construction digging and/or accidents wherein a vehicle impacts against the cable thus severing the cable and fibers therein. These disruptions are often expensive costing the various telecommunication companies involved up to $200,000 per minute for the time that the cable is inoperative. It thus becomes necessary to quickly and accurately reconnect the various fibers to each other.
As noted in copending application Ser. No. 06/921,933 filed 10/20/86, various techniques for repairing or joining cables which have been severed are known in the prior art. One prior art technique for joining cables provides that the ends of the cables to be joined together are first reduced in diameter by using a swagging technique. A portion of each end is then removed to reveal the conductors to be joined together. After the conductors have been joined together, a longitudinally slotted length of tubing is placed around the exposed joined conductors. The tubing is then filled with a suitable insulation material such as powdered mineral insulation by inserting the insulation material into the tubing through the slot. The length of the tubing is then closed by welding and connected to the cable ends by welding or brazing. The entire joint is then drawn about the conductor joint to provide the joined cables with a substantially uniform outside diameter. This technique is illustrated in U.S. Pat. No. 4,375,720 to Bourget.
A second prior art technique is disclosed in U.S. Pat. No. 4,580,874 to Winter et al. which provides a method for repairing or joining together optical fiber cables by using a ferrule to connect two optical fiber lengths. Each cable length comprises a metal tube containing one or more optical fibers and a filler material. The ferrule is placed in overlapping relationship with each tube and a lap joint is effected between the ferrule and each tube. An outer sleeve having a length substantially equal to a gap between the tubes is formed about the ferrule and is bonded to each tube. The outer sleeve preferably has an outer periphery substantially corresponding to the outer periphery of the tube so that the joined cable has a substantially continuous surface.
Other examples of prior art fiber repair kits are disclosed in U.S. Pat. Nos. 4,367,019 to Gray and 4,379,614 to Liertz.
Although providing effective means of joining fibers together of severed cables, in practice all of these prior art teachings are time consuming and do not solve the problem of the extensive cost involved overtime when such a cable is severed. Accordingly, it becomes apparent that what is needed is a quick temporary reconnection system which will repair and maintain the fibers intact until such time as an adequate substituted fiber optic cable can be placed in service in place of the temporarily repaired cable. Moreover, since the fibers have been exposed to the elements, it also becomes necessary that whatever temporary repair is effected, is done in a manner such that the fibers are containerized and hermetically sealed with respect to the environment so as to be maintained clean so that excessive losses in transmission do not result as a consequence of exposure to the elements.
Such a system is provided in accordance with this invention.